Ion pairing, H-bonding, and π-π interactions in cobalt(II) compound containing guanidinium counter ion

A novel proton transfer compound, (GH)(2)(phendc), (1), was sythesized from the reaction of 1,10-phenanthroline-2,9-dicarboxylic acid, phendcH(2), and guanidine hydrochloride, (GH)(Cl), (G: guanidine). The characterization was performed using IR, H-1 and C-13 NMR spectroscopy. The cobalt(II) compounds were synthesized using proton transfer compounds containing guanidinium counter ion. These proton transfer compounds are (GH)(2)(phendc), and (GH)(2)(pydc) (pydeH(2): 2,6-pyridinedicar-boxylic acid). The chemical formulae and space groups are (GH)(2)[Co(phendc)(2)]center dot 4H(2)O, P (1) over bar (2), and (GH)(2)[Co(H2O)(6)]-[Co(pydc)(2)](2), P2(1)/n (3). Non-covalent interactions such as ion-pairing, hydrogen bonding and pi-pi stacking are discussed.